According to conventional wisdom, if you're trying to have a kid, you should have as much sex as possible right before and during ovulation, when your ovaries release an egg. Some doctors recommend having more sex all month long — but how can that possibly help your fertility? Researchers at Indiana University think they've found the answer: It seems that having sex at all
For a pair of studies published in Fertility and Sterility and Physiology and Behavior, researchers looked at antibodies in saliva samples from 30 healthy women, 16 of whom were sexually active and 14 of whom were abstinent. They found that, during the luteal phase of the cycle, when the uterine lining thickens to prepare for implantation of a wee embryo, the sexually active women had higher levels of those helper T cells and immunoglobulins. Meanwhile, there were no shifts in immune response over the course of the abstinent women's cycles. "The sexually active women's immune systems were preparing in advance to the mere possibility of pregnancy," Lorenz noted.